Spot Colour, I am entirely new to Illustrator CS5 - My publisher tells me I have included 'Spot Colour' in the first illustrator document I sent them.

I cannot find this spot colour, or find anything that tells me if I am using spot or processed colours, or how to change from one to the other. I don't know how it happened or how to avoid it in the future - any help available ?

Check your swatches palette. Document specific colors are appended to the default swatch. Spot colors have this little white corner at the bottom. You can simply double-click and convert them to process colors by changing color mode from book to CMYK in the panel that comes up.